The need to flow materials (i.e., flowable material) through a material flow conduit is well known. Examples of such materials include, but are not limited to, fluids, slurries, particulates, flowable aggregate, and the like. Examples of such material flow conduit include, but are not limited to, pipes, pipelines, conduits, tubular flow members, and the like.
As shown in FIG. 1, conventional low of flowable material 5 within a flow passage 10 of a material flow conduit 15 has a flow profile characterized by laminar flow effect (i.e., laminar flow 20). The parabolic flow profile is a result of the laminar boundary layer along the surface of the material flow conduit 15 defining the flow passage 10. Flowable material at the surface of the flow passage 10 exhibits considerable friction and zero flow velocity, thereby reducing velocity of the flowable material even at a considerable distance from the surface of the flow passage 10. In association with this reduced velocity, the laminar flow effect (e.g., friction at the surface of the material flow conduit) is known to increase head loss and heating of the flowable material.
There are various well-known flow consideration that arises when abrasive material flows through a material flow conduit such as a pipeline. One such consideration is erosion (i.e., wearing) of the material flow conduit. Transport and pumping flowable material comprising abrasive contents, such as coal and sand slurries, wet sand, gravel and the like can cause especially high costs associated with component wear due to interaction between the flowable material and the surface defining the passage through which such material flows. Additionally, uneven erosion in piping systems, especially elbow fittings, is well known to lead to fitting failure or early fitting replacement, either of which is costly in material, manpower and downtime.
When fluids or flowable material passes through an elbow fitting, the change in direction creates turbulent conditions, flow separation and vortex shedding along the pipe wall at the inside of the bend. This change in direction may also create standing eddies causing backflow conditions at points along the elbow fitting pipe walls. These conditions generally cause the elbow fitting pipe wall along the outside of the bend to erode substantially faster than the pipe wall along the inside of the bend because the flowable material impinges directly against the wall along the outside of the bend as it enters the fitting and changes direction. Additionally, due to centrifugal force, heavier solids and particulates are generally thrown to the outside wall as the flowable material changes direction and tend to continually scour the outer wall.
A similar uneven erosion effect is often experienced in long straight pipe runs. For example, the concentration of particulates of a flowable material will increase in the lower region of the fluid in long straight runs, making the bottom portion of the fluid stream more abrasive than the upper portion. Additionally, in large diameter piping systems, the weight of the flowable material is borne by the lower pipe wall portion thereby causing higher erosion rates.
Another well-known flow consideration that arises is head loss due to turbulence and flow separation in an elbow fitting. Higher pumping pressures can be utilized for mitigating this head loss resulting from such head losses. However, higher pumping pressures are generally implemented at the expense of higher energy consumption and associated cost. Additionally, implementation of higher pumping pressures often creates vibration and heating problems in the piping system.
Long radius elbow fittings and pipe sections can reduce these adverse flow considerations. However, long radius fittings require a great deal of space relative to standard (i.e., short) radius fittings. Additionally, long radius fittings still suffer accelerated erosion rates along the pipe wall along the outside of the bend because centrifugal force still causes heavier, more abrasive flowable materials to be thrown to the outer wall, and they are continually scoured by on-going flow of such flowable material.
Therefore, a device that overcomes drawbacks associated with known flow considerations that arise from flow of abrasive material flowing through a material flow conduit would be beneficial, desirable and useful.